Cooling device of a motor for vehicle

Abstract

An oil-cooled electric motor for a vehicle including a rotational shaft rotatably supported by a casing, a rotor fixed to the rotational shaft, a stator disposed around the outer circumference of the rotor and fixed to the casing, a coil wound around the stator, and oil receiver and an oil pump mounted in the lower portion of the casing. An oil path is formed in the upper portion of the casing with openings directing oil onto the coil. An oil guide extends from one side of the casing toward the coil. Oil is pumped onto the coil via the oil path by an oil pump.

We claim: 
     
       1. An oil-cooled electric motor for a vehicle comprising: a casing;   a rotational shaft rotatably supported by the casing;   a wheel mounted on said rotational shaft;   a stator disposed around the circumference of said rotor;   a coil wound around the stator;   cooling means for supplying a flow of cooling oil onto the outer circumference of the coil; and   oil guide means, extending from one side of the casing and disposed adjacent the inner circumference of said coil, for preventing the cooling oil from running onto said rotor.   
     
     
       2. An oil-cooled electric motor according to claim 1, wherein said cooling means comprises: an oil reservoir in the lower portion of said casing;   an oil pump for circulating oil from the reservoir to the upper portion of said casing;   an outlet port for directing the cooling oil onto the other circumference of said coil; and   oil passage means for providing fluid communication between said reservoir and said output port.   
     
     
       3. An oil-cooled electric motor according to claim 2, containing oil at a level below and out of contact with said rotor. 
     
     
       4. An oil-cooled electric motor according to claim 2, wherein said casing is provided with a plurality of fins for cooling. 
     
     
       5. An oil-cooled electric motor according to claim 2, wherein said casing has a plurality of fins for cooling adjacent said reservoir. 
     
     
       6. An oil-cooled electric motor according to claim 1, further comprising: a reduction device connected between the rotational shaft and the wheel.   
     
     
       7. An oil-cooled electric motor according to claim 6, wherein said reduction device comprises: a planetary gear set including: a sun gear connected to said rotation shaft;   a carrier connected to said wheel;   a ring gear connected to the casing; and   at least one planetary gear rotatably mounted on said carrier and engaging said sun gear and said ring gear.     
     
     
       8. An oil-cooled electric motor according to claim 7, wherein said ring gear is disposed around the inner circumference of the coil. 
     
     
       9. The oil-cooled electric motor of claim 1 wherein said oil-guide means is an arc-shaped shield extending into said coil. 
     
     
       10. The oil-cooled electric motor of claim 9 wherein said arc-shaped shield is concentric with said coil and said rotor. 
     
     
       11. The oil-cooled electric motor of claim 1 wherein said cooling means comprises a plurality of jets for directing streams of falling oil onto the outer circumference of the coil. 
     
     
       12. The oil-cooled electric motor of claim 2 wherein said outlet port is formed in said casing above the outer circumference of said coil. 
     
     
       13. The oil-cooled electric motor of claim 12 further comprising an oil passage connecting said oil reservoir with said outlet port and cooling fins for cooling oil passing through said oil passage. 
     
     
       14. The oil-cooled electric motor of claim 13 wherein said cooling fins include first and second opposed sets of cooling fins on opposite sides of said oil passage.